Effective temperature scale useful for hypo- and hyperbaric environments.

Basic physics of man's heat exchange by radiation, convection, evaporation, and conduction through clothing is used to define and establish a Standard Effective Temperature Scale (SET), with which sensory and physiological responses of sedentary and active personnel can be related. The standard environment chosen is the Effective Temperature (ET) Scale, used by the American Society of Heating, Refrigerating and Air-Conditioning Engineers; namely, as the temperature of an isothermal enclosure at sea level with 50% rh and still air (0.1-0.15 m/s) in which a clothed (0.6 clo) sedentary subject would exchange the same total sensible and insensible heat as in the actual test environment. Mean skin temperature (Tsk) and skin wettedness (w) can be associated at sea level with thermal comfort and neutrality and with heat exchange. For hypo- and hyperbaric environments, thermal equivalence between SET and any test environment occurs when mean body temperature (Tb) for each is identical. Comprehensive data, developed for a 2-node model of human temperature regulation and of the associated partitional calorimetry, demonstrates the expected interaction between SET and the basic environmental and clothing factors over the barometric range 0.33 to 30 ATA.